Shaped structures including pipe and pipe fittings of organic polymeric material such as polyethylene have become widely known and used for diverse purposes such as for conveying fluids. Piping systems of polyethylene material have been found to be desirable especially in view of the ease with which such systems may be fabricated. For example, pipe fittings and pipe may be easily assembled together by utilizing chemical solvents, adhesives or heating treatments for joining these pieces, e.g., polyethylene pipe fittings may be joined to polyethylene pipe by heating the fitting and the pipe before assembly to melt the polyethylene at the region or surface of each piece to be contacted followed by mating the heated surfaces of each piece and cooling the heated pieces whereby to effect fusing of the polyethylene to provide a structure of unitary construction.
A serious problem encountered in the use of polyethylene piping systems is that resulting from the accidental rupture by excavating equipment of polyethylene pipe that is buried underground. The repair of ruptured polyethylene pipe necessitates the removal of the damaged pipe section and replacement thereof with a new section that is fused to the ends of the original pipe. The difficulty of effecting such repair resides in the fact that the fusion process for joining the replacement pipe to the original pipe requires the use of a coupling at each end of the original pipe and the use of a replacement pipe therebetween. It is not possible or feasible to effect such repair with short replacement pipe because of the lack of horizontal movement of the pipe sections required to obtain the necessary physical engagement of all of the parts to provide satisfactory fusion joining thereof. For example, it is necessary to excavate a trench for a distance of about 15 feet in each direction of a rupture of a polyethylene pipe having a diameter of 2 inches in order to utilize a replacement pipe having sufficient flexibility and slack to permit satisfactory joining of all of the parts for fusion welding. Accordingly, the principal object of the present invention is to provide a pipe fitting which can be readily joined to a conduit of polyethylene material.